The present invention relates to studies of inherited characteristics in biological organisms, and more particularly concerns pedigrees of large populations of animals or plants.
Research into diseases, drugs, and genetic mechanisms in general frequently employ pedigrees of sexually reproducing organisms for tracing the inheritance of specific characteristics through a number of generations. The right kind of pedigree display can cause relevant inheritance patterns to become readily apparent, while other pedigree configurations obscure these patterns in the details of the pedigree format.
Many applications, such as breeding, genetic selection, and gene mapping, involve large populations of animals or plants, hundreds or thousands of individuals, and matings resulting in many offspring. Conventional pedigrees bury the relevant information so deeply in the overhead of the physical representation that the pedigree is not useful in extracting particular inheritance configurations of a particular trait or condition being studied.
FIG. 1 shows an example pedigree display 100 produced by the “Pedigree Visualizer” computer program, publicly available from Kent Ridge Digital Labs. Rectangles indicate males, and ovals females; a diamond indicates unknown sex. Horizontal connectors between males and females symbolize matings. Vertical lines drop to the next generation, where horizontal bars have vertical lines to symbols for offspring of a mating. The filled symbols represent those individuals that present an inherited characteristic of interest. Pedigree 100 can accommodate only a few hundred individuals in a display that remains small enough to be in view all at once. It does not easily accommodate multiple matings or inbreeding. Depicting backbreeding is practically impossible.
FIG. 2 depicts a pedigree display 200 produced by the “Lineage” program, publicly available from the Department of Animal Science, Cornell University. This program theoretically supports large displays having hundreds or thousands of individuals. However, the relevant data, represented in the tiny dots at the lower ends of the fanned lines, is practically invisible at the size it must be drawn. Although Lineage can represent multiple matings and inbreeding, these feature add significant clutter to an already cluttered display, and further obscure the pertinent data. Backbreeding remains difficult or impossible to display adequately.